The development of the nerves of the small intestine was studied in 26 human fetuses with the gestational age of 11 to 40 weeks.The findings are as follows:(1)The distance between the Auerbach's ganglia and the muscular layer is small in the early fetal period and it increases progressively as the fetus grows.(2)The density of neuropils increases gradually.(3)The number of large gradual vacuoles (LGV) is small in the 3rd month of gestation,and it increases gradually and is quite numerous in the 6th month.(4)The morphology of the synapses is not so typical as that of an adult.(5)The peak values of the stereological morphological parameters of the organelles in the neurons appear between the 4th-6th month and maintain at a relatively high level until the baby is bron.

Thermophilic and alkalophilic xylanases have great potential in the pulp bleaching industry. In order to improve the thermal stability of an alkaline family 11 xylanase Xyn11A-LC, aromatic residues were introduced into the N-terminus of the enzyme by rational design. The mutant increased the optimum temperature by 5 degrees C. The wild type had a half-time of 22 min at 65 degrees C and pH 8.0 (Tris-HCl buffer). Under the same condition, the mutant had the half-time of 106 min. CD spectroscopy revealed that the melting temperature (T(m)) values of the wild type and mutant were 55.3 degrees C and 67.9 degrees C, respectively. These results showed that the introduction of aromatic residues could enhance the thermal stability of Xyn11A-LC.
Endo-1,4-beta Xylanases ; chemistry ; Enzyme Stability ; Hydrogen-Ion Concentration ; Protein Engineering ; Temperature

Objective To investigate the effect of estrogen on gliosis, synaptic proliferation and reorganization in hippocampus of rats with chronic epilepsy induced by pentylenetetrazol (PTZ). Methods Thirty-two Wistar rats were randomly divided into normal control group, PTZ kindling epilepsy group, estrogen+PTZ group and estrogen +Tamoxifen (mixed estrogen antagonist)+PTZ group. The PTZ kindling epilepsy group was intraperitoneally injected with 35 mg/kg PTZ once a day, then the behavior of the rats in one hour was observed. The estrogen interfered group was intramuscluarly injected of 0.6 ?g/kg ?-estradiol 6 h before PTZ injection, 1/3 d. The estrogen+Tamoxifen interfered group was injected of Tamoxifen into lateral cerebral ventricle 1 h before estrogen injection. If the severe epileptic seizures occurred three times, the rats were ready for detecting the expression of filial fibrillary acidic protein (GFAP) and synaptophysin (P38) by immunohistochemical technique. Results Epileptic seizure occoured earlier and more severely in most rats of estrogen interfered group than no estrogen interfered group. Rats in all model groups were found more astrocyte proliferation and positive synaptophysin staining, especially in the CA2, CA3 and hilar areas of dentate gyrus (DG) of hippocampus than control group. Estrogen+Tamoxifen interfered group showed significant difference as compared with other groups (P

BACKGROUND: Cyclin-dependent kinase-5 (CDK-5) is one of the members in cyclin-dependent protein kinase family. The attention has being drawn by researchers on the relationship between the expression and distribution of CDK-5 mRNA and its protein in the brain during brain development and neural degeneration in thought-cognition.OBJECTIVE: To probe into the influence of CDK-5 on neurogeny and neural degeneration during cerebral development.DESIGN: Single factor analysis of variance.SETTING: Histological and Embryological Department and Neurobiological Department in Third Military Medical University of Chinese PLA.MATERIALS: The experiment was performed in Histological and Embryological Department and Neurobiological Department in Third Military Medical University of Chinese PLA. Twenty-five Wistar rats of 5 phases were employed, named embryonicphase (E8-E21), neonatal phase (P0-P15),childhood (P16-2 months), grown-up phase (＞ 2 months) and senile phase (＞ 8 months), 5 rats in each group.METHODS: In situ hybridization histochemistry (ISH) and immunohistochemistry (IHC) staining was adopted in brain sections from embryonic phase to senile phase.MAIN OUTCOME MEASURFS: Distribution and expression of positive cells of CDK-5 mRNA and protein in various brain areas.RESULTS: Twenty-five rats entered result analysis for all. ① The expression of CDK-5 mRNA presented in entire development from E14 to P350and was in tendency of stability after growth-up. CDK-5 mRNA localized mainly in neurons and positive regions distributed mainly in cerebral cortex, hippocampus, thalamus, hypothalamus, cerebellum and a part of nerve nuclei. ② The expression of CDK-5 was strong after birth and it was weaker in embryonic and senile rats. Positive regions concentrated mainly in peripheral ventricle, hippocampus, cerebellum and a part of nerve nuclei.The expression only presented in hippocampus and Purkinje cellular layer of cerebellum in senile rats.CONCLUSION: CDK-5 in brain runs through entire phases of neural development, it expresses more significantly in neonatal phase and childhood and declines after growth-up, especially in senile phase. The declined expression of CDK-5 in hippocampus of senile rats is closely associated with decline of learning and memory in senility probably.

Objective　To evaluate the effect of Naogongfude (NGFD, a traditional Chinese medicine orally administrated) on learning and memory and the expressions of synaptophysin (SY) and Tau-protein in cerebral cortex and hippocampus in aged rats and to explore the possible mechanism. Methods　Rats were divided into normal and neural disturbance groups according to the outcomes of active avoidance reaction (AAR) test, and then each group was randomly divided into control and NGFD-treated experimental groups. Animals were orally fed with NGFD for 2 months (5 ml/d) in experimental group or routinely fed in control and taken AAR and passive avoidance reaction (PAR) tests. After the rats were sacrificed, the synaptosome count, the expression of SY and Tau-protein, and the neuron apoptosis in cerebrum were examined. Results　The rats after 2-month NGFD administration had an increased AAR acquisition, obviously delayed AAR extinction and prolonged step through latency (STL) of PAR. The number of synaptosomes was raised and the immunoreactive intensity of synaptophysin was increased remarkedly, while Tau-protein immunoreactivity and apoptotic cells were decreased in cerebrum. Conclusion　NGFD does have the effect of improving brain function and putting off the aging of rat brain according to the results of behavior study and morphological observation.

Objective To assess the efficacy of ganciclovir to prevent and cure cytomegalovirus (CMV) infection after renal transplantation. Methods We searched PubMed, EMBASE, Cochrane Library, SCI, China Academic Journals Full-text Databases, Chinese Biomedical Literature Database, Chinese Scientific Journals Databases and Chinese Medical Association Journals to collect randomized controlled trials of ganciclovir to prevent and cure CMV infection after renal transplantation (up to June, 2009). Two reviewers extracted data independently using a designed extraction form. The quality of included trials was evaluated according to the Cochrane Handbook. RevMan 5.0 software was used for data analysis. Results Twelve randomized controlled trials were included. The results of meta-analysis showed that: ①Compared with no receive antiviral agents, ganciclovir couldn't lower CMV infection rate and disease rate in 3 months and 6 months after renal transplantation, but could lower CMV disease rate in 12 months. The delay between transplantation and CMV infection was significantly longer. ②Either valaciclovir or ganciclovir could lower CMV infection rate and disease rate after renal transplantation, without statistical difference. ③Compared with acyclovir, ganciclovir could lower CMV disease rate in 6 months after renal transplantation. ④Compared with CMV-IgG and valganciclovir, ganciclovir didn't have statistical difference in decreasing CMV disease rate (P=0.93;P=0.14). Conclusions Longer prophylaxis by ganciclovior may prevent CMV infection after renal transplantation. Its curative effect is similar to valaciclovir, CMV-IgG and valganciclovir, but better than acyclovir.

Objective To evaluate the effect of serum LH level on the day of superovulation start on the prolonged gonadotropin-releasing hormone ngonist therapy on the outcomes of in vitro fertilization and embryo transfer (IVF-ET) in patents with ovarian endometriomas. Methods 75 patients with ovarian en-dometriomas were treated by laparoscopic cystectomy or laparotomy cystectomy or ultrasound-mediated cysts puncture, and gonadotropin-releasing hormone agonist (GnRH-α) was given for 3 to 4 times every 28 days after the operation. Superovulation started after 14 ～ 84 days of the last injection. All the patients were di-vided into two groups according to the level of serum LH. Group A included 30 patients whose level of LH was less than 0. 5IU/L, and group B included 45 patients whose level of LH was over 0.5IU/L and less than 1.5IU/L. The outcomes of IVF-ET were evaluated. Results The total ampoules of Gn administration and the ampoules of hMG needed in group A[(32.28±7.7) ampoules, ( 12.0±8. 9) ampoules,]were sig-nificantly more than that in group B[( 25.84±7. 1 ) ampoules, ( 6. 19±7.4) ampoules, P < 0.05] . The successful embryo implantation rate in group A( 18. 1% ) was lower than group B(26. 7% ), and the differ-ence has statistical significance ( P <0. 05). Conclusion The low level of serum LH on the superovula-lion day on the prolonged gonadotropin-releasing hormone agonist protocol will increase the ampoules of Gn administration and decrease the successful embryo implantation rate of IVF-ET, thus LH should be a more important reference parameter of superovulation start.

Objective To measure the estrogen concentration of estrogen (E 2) in the culture medium of rat astrocytes (ASTs). Methods Astrocytes in brain cortex of the 2-day-old neonatal rats were collected and cultured. The number of astrocytes was counted and the concentration of estrogen was measured by ELISA method at 0, 7, 14, and 21 d after culture. Results The cell counts were 1?10 4/ml, 1.1?10 6/ml, 1.4?10 6/ ml, and 1.5?10 6/ml, respectively. The concentrations of E 2 were: 0 pg/ml, (117.03?21.32) pg/ml, (266.91?22.03) pg/ml, and (252.62?27.99) pg/ml, respectively. No estrogen was detected in the primary culture medium. The concentration of estrogen increased in a time-dependent manner and reached the peak at 14 d, and then decreased gradually but remained at a certain level. Conclusion E 2 is secreted by astrocytes in the brain cortex of the 2-day-old neonatal rats.

Objective To detection the methylation of p16INK4A in primary hepatocellular carcinoma, a nested bisulfite sequencing and methylation-specific polymerase chain reaction (BS-MSP) protocol was designed and used.Methods Bisulfite-modified DNA were amplified to evaluate the quality of templates with a pair of bisulfite sequencing primers in the first round of PCR, then subjected to methylation assay with corresponding methylation or unmethylation specific PCR primers.Representative PCR products were sequenced to confirm its correctness.Results 3 of 40 cases (7.5%) were failed to assay due to poor quality of templates, and 29 of 37 cases (78%) were detected p16INK4A methylation.Sequencing results confirmed that templates were correctly amplified.Conclusion BS-MSP technique might be valuable for methylation study on carcinogenesis and clinical assay.

Objective To study the effect of astrocyte on synapse formation and the molecular mechanism. Methods Cortical astrocytes were isolated and purified from neonatal rats.On the 2h,7th day,14th day and 21th day after passage,we counted the number of astrocytes and the culture medium(astrocyte-conditioned medium,ACM)was harvested to measure the concentration of estrogen(E 2)by using ELISA techniques.Based on the model of pure culures of neonatal cortical neurons,the experimental groups were designed as follows:1.pure neuron cultures(group N);2.ACM cultures(group A);3.mixed cultures(group M);4.E 2 cultures(group E 2);5.ACM+Tamoxifen(estrogen receptor antagonist)cultures(group A+T);6.Tamoxifen cultures(group T).Then synaptic puncta in every group was stained and counted through immunofluorescence,and we also compared the differences in puncta number among those six groups(at 9th day in culture,number/per neuron). Results The numbers of astrocytes were:1?10 4/ml, 1.1?10 6/ml, 1.4?10 6/ml, 1.5?10 6/ml; The concentrations of E 2 were:(ng/L):0, 117?22, 266?22,252?27 respectively.No estrogen was detected in the primary culture medium.The concenteration of estrogen increased in correspondence with the culturing days and reached the peak around at the 14th day, then decreased gradually but kept at a certain high level,and the numbers of synaptic puncta of per neuron in group N,A,M,E 2,A+T,T were:14?3;79?5;83?8;80?6;32?3;29?3 respectively.The treatment of pure neuron culture with ACM increased the number of synapses on per neuron by up to 6 fold by comparison with pure neuronal culture.Exogenic estradiol added into pure neurons can mimick the effect of the ACM.Tamoxifen which is antagonist of estrogen receptor could decrease the effect of ACM by 75%.Conclusion The astrocytes of neonatal rat cortex do secrete E 2.Astrocyte-derived estrogen may be the molecule regulating the synaptic formation through estrogen receptors.